nvdimm/btt: reject an arena whose nfree is below the lane count
In the Linux kernel, the following vulnerability has been resolved: nvdimm/btt: reject an arena whose nfree is below the lane count The BTT info block's nfree field, the number of reserve free blocks, is read from the medium without validation. btt_freelist_init() and btt_rtt_init() size the per-lane freelist[] and rtt[] arrays by nfree, but the I/O path indexes them by the lane from nd_region_acquire_lane(), which is bounded by nd_region->num_lanes (ND_MAX_LANES), not by nfree. A crafted or foreign arena whose nfree is below the lane count makes freelist[lane]/rtt[lane] run past the allocation: an out-of-bounds write. btt.rst documents the nlanes = min(nfree, num_cpus) invariant, which the code does not currently honor: num_lanes is ND_MAX_LANES regardless of nfree. Reject an arena whose nfree is below num_lanes at discovery, before the per-lane arrays are allocated, enforcing that invariant.
CVE-2026-89965
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-89965
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "eb491343d2d1784121ad9af91c25b338c28913c3",
"versionType": "git"
},
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "59d5cd1f42b4bab3609512c3cb3d3540d3d21da7",
"versionType": "git"
},
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "f6c5313aae794ecca8f762c1a3493de5c266f120",
"versionType": "git"
},
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "f9bf05c63b77d000e9c01f3e47af36973887d350",
"versionType": "git"
},
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "6f79d1a5f2611a3d36e9312be5425cd9cb397c51",
"versionType": "git"
},
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "6b1faf1f099f7060b5f1f2f0d024132581f1726e",
"versionType": "git"
},
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "9dfa11cef4750b67591307f2c62e47a23d60e4b7",
"versionType": "git"
},
{
"status": "affected",
"version": "5212e11fde4d40fa627668b4f2222d20db488f71",
"lessThan": "6a1f2e5ed9267ca19187038ac635393c165213ac",
"versionType": "git"
}
],
"programFiles": [
"drivers/nvdimm/btt.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/nvdimm/btt.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89965
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #36404 · Revision 1
- Added to Heist Feed
- Publisher date